The immediate goals of the project are further work on determining the mechanisms of and discovering new reactions of the prostaglandin endoperoxide nucleus, various models of and the natural endoperoxides themselves. A synthetic enzyme which will selectively catalyze disproportionation is to be prepared, and a synthesis of the thromboxane A2 nucleus will be developed. Occasionally nature provides us with molecules which not only have unusual structures, but which also exhibit extraordinary chemical reactivity which is crucial to their biological roles. Prostaglandin endoperoxides and thromboxane A2 are pertinent examples which possess unusual heterobicyclic nuclei. Our studies of the prostaglandin endoperoxide nucleus have clearly shown that the chemistry of this strained bicyclic peroxide is unique and cannot be predicted by simple extrapolation of the behavior of any dialkylperoxides. Our studies on the chemistry of simple models will guide parallel studies of the natural products and eventually provide a basis for understanding prostaglandin endoperoxide and thromboxane biochemistry.